The present invention relates to mechanical devices for removing and destroying insects and related pests from cultivated crops.
Demand for non-chemical methods of controlling insect and related pests has dramatically increased in recent years. Many factors have contributed to discourage reliance exclusively on chemical pesticides. Significant among these are: concern for the environmental impact and consumer health risks of many pesticides; government restrictions on use or availability of certain pesticides; and, development of resistant varieties of pests resulting from prolonged use of pesticides, obliging ever increasing concentrations of the pesticide for effective control.
Scientists are therefore continually searching for new methods of plant pest control in an effort to maintain production while decreasing the risks to both the environment and the consumer. Infrared light, ultrasound, radiation, pheromone traps, injecting natural predators of pests into the plant environment, and integrated pest management are but a few of the general areas of inquiry that merit ongoing research Perhaps a solution lies also in a "refinement of the past".
Before the advent of chemical pesticides, various nonchemical and mechanical pest control systems were utilized in different agricultural systems. Certain techniques for steaming the soil before seeding were common, in an attempt to burn insect eggs and weed seeds. A similar effect was obtained by controlled burning of fields after harvesting of some annual crops.
As mechanized implements dramatically increased tillage and production, so too, plant pests thrived in the vast "monoculture" fields because such large fields disturbed the normal balance of predator and pest. Insects, in particular, became the scourge of large plantings, devastating thousands of acres in a matter of days At the beginning of this century, clouds of "locusts" and similar insect pests darkened the skies over American agriculture.
Perhaps no crop was economically more important at that time than cotton. With powered machinery replacing much of the required manual labor, cotton acreage increased significantly. Simultaneously, the major cotton insect pest, a beetle known as the "boll weevil", became an ever growing threat and major concern for cotton growers.
Because of both the unique characteristics of the boll weevil and the structure of the cotton plant at the time it is susceptible to boll-weevil attack, a mechanized suction technology developed to control the pest. The boll weevil, like most beetles, flies only irregularly, when under extreme alarm or out of food. Additionally, unlike many insects, the boll weevil clings loosely to plants. Consequently, suction devices were especially effective against boll weevils because they did not fly out of the way of advancing, noisy, machines and they were easily dislodged from the plants.
The boll-weevil suction exterminators started as horse drawn machines. Blowers were powered by gears from the pulled wheels, and agitation bars were used to knock the insects off the plants into the paths of advancing shovel or funnel-like suction devices.
Eventually, improved models included handheld suction hoses that were walked along, beside and in front of the pump apparatus. Some exterminators even used screened vacuum chambers (like present day porous bag vacuum cleaners) to prevent sucked debris from contacting the pumps.
As the technology advanced through the 1920's and 1930's, exterminators began to utilize the exhaust or discharge side of the blowers to first direct the fallen insects into the path of the suction scoops and, finally, to agitate the insects off the plant. One such exterminator is described in U.S. Pat. No. 2,201,463 to Williams et al.
Williams describes an insect vacuum with a single-chamber rotary blower attached to a shoe-like suction device (illustrated in FIG. 8 of the present application). The pump's discharge blows air, through a conduit, into the bottom of the shoe, where it is ejected upwardly and inwardly into a plant chamber. The pump's intake is attached to the top of a central collection pipe of the shoe (not shown). It sucks the injected air, along with collected pests and debris, through the pipe and into the pump's impeller chamber, where they are destroyed and chopped by the spinning blades. The insect pieces then pass through the discharge and are "re-injected" into the bottom of the hood. There, the fragments allegedly assist in additional plant agitation by hitting live insects to knock them off the plant and into the suction conduit.
The primary problem with those prior suction exterminators was that their potential for widespread application was inherently limited by the structure mandated for effective boll weevil control. First, those exterminators utilizing hood collectors such as Williams et al., had to be sufficiently tall to adequately enclose the cotton plants. Therefore, they had no ability to apply to lower growing plants such as potatoes, onions or cucumbers. Second, the exterminators utilizing suction funnel or scoop types of collectors had insufficient suction to suck the stronger or smaller insect pests off lower growing plants. Merely increasing the suction of these types of exterminators would cause excessive soil and ground debris to enter and clog the suction lines and pumps.
Additionally, suction exterminator technology was abandoned before two other related problems were solved. All known prior suction exterminators utilized single-chamber blowers or pumps, wherein the insects or debris were either fed into the pumps, to be recycled, such as in Williams et al., or stored in screened manifolds or porous containers. Increasing suction forces of the former inherently caused the recycled debris to sometimes injure the subject plant; and, the "vacuum cleaner" type suffered from constantly decreasing suction forces as the storage reservoirs filled.
Consequently, because of structural limitation, known suction exterminators are inherently incapable of effective application on low growing plants, such as potatoes, onions or cucumbers. Further, for the same reason, they are incapable of applying sufficient suction forces to extract from those low growing plants stronger and smaller pests, such as Colorado potatoe beetles and immature (larval) forms of pest insects and aphids.
Accordingly, it is the general object of the present invention to provide an improved suction insect eradicator that overcomes the problems of the prior art.
It is another general object to provide an improved suction insect eradicator that provides an inexpensive alternative to costly pesticides.
It is a more specific object to provide a suction insect eradicator for removing and destroying strong small insects and related pests from low growing plants, such as potatoes, onions or cucumbers.
It is another object to provide a suction insect eradicator with a highly variable suction current that can be varied to remove insects in their differing stages of development (larval, adult, etc.) without damaging the subject plants.
It is yet another object to provide a suction insect eradicator with a specially designed hood that covers the subject plant and shields the nearby ground to prevent "outside" soil particles or associated debris from being drawn into the exterminator.
It is still another object to provide a suction insect eradicator, commensurate with the above-listed objects, which can be easily affixed to a common farm tractor's rear "three-point hitch" and powered by the tractor's rear "power takeoff" shaft.
The above and other objects and advantages of this invention will become more readily apparent when the following description is read in conjunction with the accompanying drawings.